Aside from stating the obvious, I mean that the Commerce Department’s National Institute of Standards and Technology (NIST) recently announced that changes to U.S. model building and fire codes based on recommendations from NIST’s World Trade Center (WTC) Towers investigation were approved at the final action hearings of the International Code Council (ICC) in Minneapolis on Sept. 15-21, 2008, and will be incorporated into the 2009 edition of the ICC’s I-Codes, including the International Building Code (IBC).

According to a statement released by NIST, following are 11 of the 23 model building and fire code changes consistent with the NIST WTC investigation recommendations that will impact structural engineers the most:

• an additional (third) exit stairway for buildings more than 420 feet high;
• an increase of 50 percent in the width of exit stairways in new sprinklered buildings;
• hardening of exit stairway and passageway enclosures, and elevator shaft enclosures for all buildings more than 420 feet high and for buildings 75-420 feet high where failure of the enclosure would substantially jeopardize human life, and in essential facilities such as hospitals;
• a minimum of one fire service access elevator for buildings more than 120 feet high;
• providing minimum structural integrity for framed and bearing wall structures;
• a one-hour increase in the fire-resistance rating of structural components and assemblies in buildings more than 420 feet high;
• explicit adoption of the "structural frame" approach to fire resistance ratings that requires all members of the primary structural frame to have the higher fire resistance rating commonly required for columns;
• broadening the definition of the primary structural frame to include bracing members essential to vertical stability (such as floor systems or cross bracing) whether or not they carry gravity loads;
• increasing bond strength for fireproofing to nearly three times greater than what is currently required for buildings 75-420 feet high and seven times greater for buildings more than 420 feet high;
• additional field installation requirements for fireproofing; and
• special field inspections of fireproofing.

The following are three of the nine model building and fire code change proposals that were not approved for the 2009 edition of the I-Codes, but will be considered for resubmission at a later date after being amended:

• requiring buildings more than 420 feet high to be designed to survive a building contents fire to burnout without more than local failure of the structural frame;
• requiring structures not to suffer a collapse disproportionate to a local initiating failure caused by an incident; and
• requiring use of a new standard for conducting wind tunnel testing.

See "Code changes from NIST WTC investigation slated for 2009 IBC" on page 10 for more and visit www.gostructural.com for the complete NIST statement.

While it will take some time for the ICC to complete the 2009 IBC, and even longer for jurisdictions to adopt the 2009 model codes, impacts that will result from these adopted NIST recommendations can be easily anticipated in a building’s program, particularly in stair layouts. As the industry reveals what these changes mean to building design and construction, I will do my best to keep you informed.

In the meantime, I wish you a peaceful and productive 2009—this time I do mean the obvious!